Size of Atoms and Ions

Q.

Define lanthanoid contraction and mention its consequences?

Q. The correct order of ionic radii of $Ce,La,Pm$ and $Yb$ in its $+3$ oxidation state is:

1. $L{a}^{3+}<P{m}^{3+}<C{e}^{3+}<Y{b}^{3+}$
2. $L{a}^{3+}<C{e}^{3+}<P{m}^{3+}<Y{b}^{3+}$
3. $Y{b}^{3+}<C{e}^{3+}<P{m}^{3+}<L{a}^{3+}$
4. $Y{b}^{3+}<P{m}^{3+}<C{e}^{3+}<L{a}^{3+}$

Q.

Explain actinoid contraction. f- block

Q.

What is the difference between transition and d block element😢😢😢

Q. The maximum & minimum melting point of first transition and second transition series elements, respectively are obtained with:

1. Cr & Cd
2. Cr & Hg
3. Mo & Cd
4. Cr & Zn

Q. Which one of the following lanthanoids does not form $M{O}_2?$
($M$ = Lanthanoid element)

1. $Nd$
2. $Yb$
3. $Dy$
4. $Pr$

Q.

d-block elements are also called as:

1. Electropositive elements

2. Transition elements

3. Inner transition elements

4. Representative elements

Q. Which of the following element belongs to the second transition series of the periodic table?

1. Ni
2. Au
3. La
4. Nb

Q.

Which of the following group of elements belongs to 4d transition series?

1. W , Re , Os

2. V , Cr , Co

3. Ti, Zr , Hf

4. Zr , Nb, Mo

Q. The time taken by the electron in one complete revolution in the $n^{th}$ Bohr's orbit of the hydrogen atom is:

1. Directly proportional to $\frac{n^3}{Z^2}$
2. Inversely proportional to $n^2$
3. Directly proportional to $\frac{h}{2\pi }$
4. Inversely proportional to $\frac{n}{h}$

Q. Which graph represents the correct trend in atomic radii of transition elements?

1. 
2. 
3. 
4. 

Q. The correct order of ionic radii for $Y^{3+},E{u}^{3+},L{a}^{3+},L{u}^{3+}$

1. 
2. 
3. 
4. 

Q. Which of the following pair/s have nearly same size?

1. $Zr,Hf$
2. $Nb,Ta$
3. $Fe,Zn$
4. $K,Rb$

Q. The atomic radius of $Ag$ is closest to:

1. $Cu$
2. $Hg$
3. $Ni$
4. $Au$

Q. What are the causes of lanthanide contraction?

Q. Similar sizes of second and third transition elements can be explained on the basis of −

1. Inert-pair effect
2. Screening effect
3. Lanthanide contraction
4. Increasing effective nuclear charge

Q. What is maximum covalency of phosphorus ?

Q. The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?

Q. Why zinc is not a transition element?

Q. What is the nature of the transition elements?

1. Metallic
2. Non-metallic
3. Metalloid
4. Varies from element to element

Q. Choose the correct relation on the basis of bohr's theory.

1. $\text{Velocity of electron}\propto \frac{1}{n}$
2. $\text{Frequency of revolution}\propto \frac{Z^2}{n^3}$
3. $\text{Radius of orbit}\propto \frac{n^2}{Z}$
4. $\text{Force on electron}\propto \frac{Z^3}{n^4}$

Q. Zinc, Cadmium and mercury shows the property of

1. Typical elements
2. Normal elements
3. Transition elements
4. Rare elements

Q.

Which of the following is a metal: ${}_{11}{}^{23}\mathrm{X}$ or ${}_9{}^{19}\mathrm{Y}$?

Q. The lanthanide contraction is responsible for the fact that

1. and have about the same radius
2. and have about the same radius
3. and have similar oxidation state
4. and have the same oxidation sate

Q. Elements which occupied the position in the Lother Meyer curve, on the peaks, were:

1. alkali metals
2. highly electropositive elements
3. elements having large atomic volume
4. all of the above

Q. Zinc, Cadmium and mercury shows the property of

1. Typical elements
2. Transition elements
3. Normal elements
4. Rare elements

Q. The elements of the three transition series of the d - block are given below:
$\begin{array}{cccccccccc}& & & & & & & & & \\ Sc& Ti& V& Cr& Mn& Fe& Co& Ni& Cu& Zn\\ Y& Zr& Nb& Mo& Tc& Ru& Rh& Rd& Ag& Cd\\ La& Hf& Ta& W& Re& Os& Ir& Pt& Au& Hg\end{array}$
In any transition series, as we move form left to right, the d - orbitals are progressively filled and their properties vary accordingly.
Which element do you expect to have the highest melting point?

1. La
2. W
3. Os
4. Pt

Q. The lanthanide contraction is responsible for the fact that

1. Zr and Y have about the same radius
2. Zr and Nb have similar oxidation state
3. Zr and Hf have about the same radius
4. Zr and Zn have the same oxidation sate

Q. A reduction in atomic size with increase in atomic number is a characteristic of elements of

1. Radioactive series
2. High atomic masses
3. f –block
4. d-block

Q. Which of the following have highest ionic radii

1. $F{e}^{3+}$
2. $C{r}^{3+}$
3. $M{n}^{3+}$
4. $C{o}^{3+}$